Abstract
The present invention relates generally to a spoke reinforcing method and reinforced structure of spokes, the method includes a main body of spoke with a head end and a thread part on two ends respectively, a neck is disposed below the head end, the neck is forged at least twice to enlarge the cross-section area of the neck, and to increase the density and strength of the metal grains therein; a hexagonal columnar reinforced structure is forged below this high density neck, and the high frequency lateral stress on the lower part of the high density neck is buffered by the optimal compressive strength and flexural strength of the hexagonal column, the reinforced structure of spokes produced by this method can reduce the spoke fracture probability and prolong the spoke lifetime.
Claims
1. A spoke reinforcing method, including the following steps: straightening and cutoff, the drawn spoke is straightened and cut to the required length; first forging, one end of said spoke is stamped by a first stamping unit to form the initial head and neck; clamp forming, the head, neck and main body of spoke of the initial formed spoke are clamped by a clamping die, the shape of the reinforced part is forged during clamping; second forging, the spoke clamped by the same clamping die is stamped by a second stamping unit, so as to form the final head, neck and reinforced part; hobbing, the end opposite to the head of said spoke is hobbed to form a thread part.
2. The spoke reinforcing method defined in claim 1, a bending step can be created between the second forging and hobbing steps to bend the neck of the formed spoke.
3. The spoke reinforcing method defined in claim 1, wherein the cross-sectional shape of the reinforced part is any one of polygons.
4. The spoke reinforcing method defined in claim 1, wherein the cross-sectional shape of the reinforced part is hexagonal or rectangular.
5. The spoke reinforcing method defined in claim 1, wherein the length of the reinforced part is at least 5 mm.
6. A reinforced structure of spokes, including a main body of spoke, a head, a neck and a reinforced part are arranged in turn from the edge of one end of the main body of spoke, the other end is provided with a thread part.
7. The reinforced structure of spokes defined in claim 6, wherein the cross-sectional shape of the reinforced part is hexagonal or rectangular.
8. The reinforced structure of spokes defined in claim 6, wherein the spoke forms include straight-pull spoke and elbow spoke.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is the outside view of a conventional spoke.
[0016] FIG. 2 is the outside view of a conventional reinforced spoke.
[0017] FIG. 3 is the schematic diagram of conventional improved spokes installed on wheel.
[0018] FIG. 4 is the schematic diagram of tensile test for conventional improved spoke.
[0019] FIG. 5 is the schematic diagram of fatigue test for conventional improved spoke.
[0020] FIG. 6 is the schematic diagram of tensile test for conventional improved spoke with improved tilt angle.
[0021] FIG. 7 is the schematic diagram of fatigue test for conventional improved spoke with improved tilt angle.
[0022] FIG. 8 is the schematic diagram of rupture of conventional improved spoke.
[0023] FIG. 9 is the schematic diagram of grain density of conventional improved spoke.
[0024] FIG. 10 is the outside view from different viewing angles of the reinforced structure of spokes of the present invention.
[0025] FIG. 11 (A) (B) show the flow charts of the present invention for different spokes.
[0026] FIG. 12 (A) (B) are the actual process diagrams I and II of the spoke reinforcing method for different spokes of the present invention.
[0027] FIG. 13 is the implementation application illustration of the spoke reinforcing method of the present invention.
[0028] FIG. 14 is the schematic diagram of grain density of the reinforced structure of spokes of the present invention.
[0029] FIG. 15 shows the fatigue test results of the reinforced structure of spokes of the present invention, conventional spoke and conventional improved spoke at different tilt angles.
DETAILED DESCRIPTION OF THE INVENTION
[0030] FIGS. 10?14 disclose the spoke reinforcing method in a preferred embodiment of the present invention. First, a metal material is drawn into an elbow spoke of the required diameter. The metal material includes, but not limited to stainless steel, carbon steel, titanium alloy, aluminum alloy, etc. The spoke production methods include straight-pull spoke and elbow spoke, taking the elbow spoke production method as an example, as shown in FIG. 11 (B), the procedure includes straightening and cutoff (001), the drawn spoke (1) is straightened and cut to the required length; first forging (002), one end of the spoke (1) is stamped by a first stamping unit to form the initial head (2) and neck (3); clamp forming (003), the head (2), neck (3) and main body of spoke (1) of the initial formed spoke (1) are clamped by a clamping die, the shape forging of the reinforced part (4) is completed during clamping, a hexagonal column is taken as an example in this embodiment (including, but not limited to triangular prism, quadrangular prism or arbitrary polygonal column); second forging (004), the spoke (1) clamped by the clamping die is stamped by a second stamping unit, so as to form the final head (2), neck (3) and reinforced part (4); bending (005), the neck (3) of the formed spoke (1) is bent; hobbing (006), the end opposite to the head (2) of said spoke (1) is hobbed to form a thread part (5), thus reinforced structure of spokes is completed, as shown in FIG. 10.
[0031] The straight-pull spoke production method is shown in FIG. 11 (A), the procedure is free of the bending (005) process, including straightening and cutoff (001), first forging (002), clamp forming (003), second forging (004) and hobbing (006).
[0032] The clamp forming (003) in said reinforced spoke manufacturing method includes the second forging (004) process. It is noteworthy that the neck (3) and reinforced part (4) of the spoke (1) must be forged in the same clamping die, so as to make sure the grain density of the processed head (2), neck (3) and reinforced part (4) of the spoke (1) is continuous and unfaulted, as shown in FIG. 14.
[0033] As shown in FIG. 10, the reinforced structure of spokes manufactured according to said spoke reinforcing method includes a main body of spoke (1), a head (2), a neck (3) and a reinforced part (4) are arranged in turn from the edge of one end of the main body of the spoke (1), the other end is provided with a thread part (5). Particularly, the cross-sectional shape of the reinforced part (4) is hexagonal (or rectangular and a polygonal) structure type, and it is experimentally proved that the optimal compressive strength and flexural strength can be achieved using minimum quantity of materials.
[0034] FIG. 15 discloses the fatigue test results of the spoke of the present invention, conventional spoke and conventional improved spoke; the left side is the fatigue test (times), the lower PK represents conventional spoke, PSR represents the improved spoke, PHR is the reinforced structure of spokes of the present invention, the left side of each histogram is 0? (standard vertical fatigue test), the right side is 10? (tilt angle fatigue test), in the same test condition, the same raw material, the same production equipment, the same test equipment and the same fixture are used to perform fatigue test (180 Kgf, 10 Hz) for the conventional spoke, improved spoke and reinforced structure of spokes; it is observed in the chart that the data of the reinforced structure of spokes of the present invention have better performance than conventional spoke and conventional improved spoke in 0? (standard vertical fatigue test) or 10? (tilt angle fatigue test). The experiment data prove that the spoke strength can be improved greatly after the fragile part of the conventional improved spoke is improved into a hexagonal columnar reinforced part structure type according to the correct processing procedure.
[0035] According to the above description, the spoke reinforcing method of the present invention proposes forging a reinforced part (hexagonal columnar or rectangular) connected to the forged neck, because the area 1?3 mm below the neck thickened by multiple times of forge processing will become the fatigue/fracture hot zone, so as to substitute the unforged cylindrical spoke at the conventional joint, the reinforced part in this shape has the best compressive strength and flexural strength, so as to buffer the high frequency lateral stress on the joint below the neck of high density grains, and to improve the endless fracture accidents, meanwhile the spoke fracture probability is reduced, and the spoke lifetime is prolonged.
[0036] Although the invention has been explained in relation to its preferred embodiment, it is to be understood that many other possible modifications and variations can be made without departing from the spirit and scope of the invention as hereinafter claimed.
